u can try ediitng some grnd for this lol but i try to stay away from to complicatted as u got to tell everyone everytime how the units are.
plethora2ecspread-custom warground
use map settings only!! use starting resource low mid or high.
gold is only resource which u still need a good flow to keep up.
guard tower-long range weaker air grnd.
canon-heavy air grnd shorter range.
bship-flying cat can attack grnd only
subs-air attack only
ballistas- shorter range than birds but dam deadly! air and grd! effecient at ridding ships
birds- heavy long range grnd only. a fortified towns worst nightmare.
other than that all stock units modified weapon sprites to distinguish from orc and human.
Use map settings map!